Defining “View Source”

September 10, 2020

Last time there was a little flurry of activity around the concept of “View Source,” I did get the sense that not everyone was on the same page about what that even means. Jim Nielsen:

First, when we talk about “View Source” what precisely are we talking about? I think this is an important point to clarify, as it sometimes goes unsaid and therefore a lot of assumptions sneak into the conversation and we might realize we’re not all talking about the same thing.

There are three things that people might be talking about:

  1. View source code (the code that generates the HTML delivered over the network)
  2. View page source (the HTML delivered over the network)
  3. View runtime source (the living HTML, a.k.a the DOM)

I’ll assign what I think are the values of each are, as slices of a pie chart:

  1. 10%
  2. 5%
  3. 85%

Every major browser ships with built-in DevTools where you can easily peak at the “runtime source.” That’s where the vast bulk of value is to me. If browsers ever talked about removing that, I’m sure we’d all be up in arms. Even for non-developers, the existence of this tool might be the spark that grows baby web developers.

DevTools also provides a way to view the HTML delivered over the network, hence my hardline stance from before:

I literally don’t care at all about View Source and wouldn’t miss it if it was removed from browsers. I live in DevTools, and I’ll bet you do too. It entirely supersedes View Source, as you can quite literally view source inside it if you’d like.

Jim’s post explains the difference between all three types of “viewing source” in great detail. For sites that are built entirely from client-side JavaScript, viewing the HTML over the wire is nearly useless. But if you could see the whole codebase (say if it was open-source on GitHub), there is certainly value there.